2004/04/19

Los Angeles

"The problem, however, is that it creates many more nitrogen oxides (NOx) than traditional diesel - as much as 12 percent higher according to a 2002 consultant report commissioned by the South Coast Air Quality Management District, which regulates air locally."

Biodiesel from vegetable oils produces less particulate matter, more NOx and more engine impact (meaning it can wear out or dissolve engines parts more quickly than regular diesel).

When biodiesel is blended with traditional diesel, PM counts lower dramatically, NOx increases are less severe and the biodiesel inventory can be stretched.

If all the waste oil that the 15 million people in the South Coast air basin produce each year was turned into biodiesel, there would be enough to make about 18 million gallons each year. That's just higher than 1 percent of our local diesel consumption.

"The NOx is a result of temperature,' he said. "The diesel engine needs to reach a certain temperature to run and that produces NOx, so you're always going to have NOx.'